Table 4

Concurrent validity, internal reliability and repeatability of the King's Brief Interstitial Lung Disease (K-BILD) questionnaire in idiopathic pulmonary fibrosis (IPF); comparison with other interstitial lung diseases (ILDs)

K-BILD Total score
SGRQ Total−0.9−0.9
SGRQ Sym−0.7−0.7
SGRQ Act−0.8−0.8
SGRQ Imp−0.9−0.9
FVC %0.60.4
TLCO %0.4*0.5
Internal reliability (Cronbach's α coefficient)0.90.9
Repeatability (intraclass correlation coefficient)0.90.9
  • Data shown are Pearson's correlation coefficients unless otherwise stated. p<0.01 or *p<0.05.

  • FVC, forced vital capacity; SGRQ, St George's Respiratory Questionnaire; SGRQ Act, SGRQ – Activity; SGRQ Imp, SGRQ – Impact; SGRQ Sym, SGRQ – Symptoms; TLCO, diffusing capacity of the lung for carbon monoxide as % predicted.